Research Square (Research Square),
Journal Year:
2022,
Volume and Issue:
unknown
Published: Dec. 22, 2022
Abstract
In
the
traditional
linked
simulation-optimization
method,
solving
optimization
model
requires
massive
invoking
of
groundwater
numerical
simulation
model,
which
causes
a
huge
computational
load.
present
study,
surrogate
origin
was
developed
using
Bidirectional
Long
and
Short-term
Memory
neural
network
method
(BiLSTM).
Compared
with
models
built
by
shallow
learning
methods
(BP
network)
LSTM
methods,
BiLSTM
has
higher
accuracy
better
generalization
performance
while
reducing
The
to
solved
Sparrow
Search
Algorithm
based
on
Sobol
sequences
(SSAS).
SSAS
enhances
diversity
initial
population
sparrows
introducing
introduces
nonlinear
inertia
weights
control
search
range
efficiency.
SSA,
stronger
global
ability
faster
And
identifies
contamination
source
location
release
intensity
stably
reliably.
This
study
also
applied
Cholesky
decomposition
establish
Gaussian
field
for
hydraulic
conductivity
evaluate
feasibility
method.
Frontiers in Public Health,
Journal Year:
2022,
Volume and Issue:
10
Published: May 26, 2022
The
traditional
risk
management
and
control
mode
(RMCM)
in
regional
sites
has
the
defects
of
low
efficiency,
high
cost,
lack
systematism.
Trying
to
resolve
these
explore
application
possibility
machine
learning,
a
characteristic
dataset
for
RMCM
was
established.
Three
decision
tree
(DT)
algorithms
(CHAID,
EXHAUSTIVE
CHAID,
CART)
two
artificial
neural
network
(ANN)
[back
propagation
(BP)
radial
basis
function
(RBF)]
were
implemented
predict
sites.
results
showed
that
aspects
accuracy
(ACC),
precision
(PRE),
recall
ratio
(REC),
F
1
value,
CART–DT
superior
CHAID–DT
(E-CHAID–DT);
BP–ANN
RBF–ANN.
However,
inferior
ACC,
PRE,
REC,
value.
model
is
good
at
non-linear
mapping,
it
flexible
structure
over-fitting.
case
study
typical
county
demonstration
area
confirmed
extensibility
method,
method
great
potential
prediction
future.
Hydrology and earth system sciences,
Journal Year:
2024,
Volume and Issue:
28(1), P. 179 - 203
Published: Jan. 11, 2024
Abstract.
Backward
probabilities,
such
as
the
backward
travel
time
probability
density
function
for
pollutants
in
natural
aquifers/rivers,
have
been
used
by
hydrologists
decades
water
quality
applications.
Calculating
these
however,
is
challenging
due
to
non-Fickian
pollutant
transport
dynamics
and
velocity
resolution
variability
at
study
sites.
To
address
issues,
we
built
an
adjoint
model
deriving
a
backward-in-time
fractional-derivative
equation
subordinated
regional
flow,
developed
Lagrangian
solver,
applied
model/solver
trace
diverse
flow
systems.
The
subordinates
reversed
field,
transforms
forward-in-time
boundaries
into
either
absorbing
or
reflective
boundaries,
reverses
tempered
stable
define
mechanical
dispersion.
corresponding
solver
efficiently
projects
super-diffusive
dispersion
along
streamlines.
Field
applications
demonstrate
subordination
model's
success
with
respect
recovering
release
history,
groundwater
age,
source
locations
various
These
include
systems
upscaled
constant
velocity,
nonuniform
divergent
fields,
fine-resolution
velocities
nonstationary,
regional-scale
aquifer,
where
significantly
affects
probabilities.
Caution
needed
when
identifying
phase-sensitive
(aqueous
vs.
absorbed)
media.
also
explores
possible
extensions
of
quantifying
probabilities
more
complex
media,
discrete
fracture
networks.
Abstract.
Backward
probabilities
such
as
backward
travel
time
probability
density
function
for
pollutants
in
natural
aquifers/rivers
had
been
used
by
hydrologists
decades
water-quality
related
applications.
Reliable
calculation
of
probabilities,
however,
has
challenged
non-Fickian
pollutant
transport
dynamics
and
variability
the
resolution
velocity
at
study
sites.
To
address
these
two
issues,
we
built
an
adjoint
model
deriving
a
backward-in-time
fractional-derivative
equation
subordinated
to
regional
flow,
developed
Lagrangian
solver,
applied
model/solver
backtrack
various
flow
systems.
The
applies
subordination
reversed
field,
converts
forward-in-time
boundaries
either
absorbing
or
reflective
boundaries,
reverses
tempered
stable
define
mechanical
dispersion.
corresponding
solver
is
computationally
efficient
projecting
super-diffusive
dispersion
along
streamlines.
Field
applications
demonstrate
that
can
successfully
recover
release
history,
dated
groundwater
age,
spatial
location(s)
source(s)
systems
with
upscaled
constant
velocity,
non-uniform
divergent
fine-resolution
velocities
non-stationary,
regional-scale
aquifer,
where
significantly
affects
characteristics.
Caution
needed
when
identifying
phase-sensitive
(aqueous
versus
absorbed)
source
media.
Possible
extensions
are
also
discussed
tested
quantifying
more
complex
media,
discrete
fracture
networks.
Research Square (Research Square),
Journal Year:
2023,
Volume and Issue:
unknown
Published: July 31, 2023
Abstract
In
the
optimal
design
of
groundwater
pollution
monitoring
network
(GPMN),
uncertainty
simulation
model
always
affects
reliability
when
applying
simulation–optimization
methods.
To
address
this
issue,
in
present
study,
we
focused
on
source
intensity
and
hydraulic
conductivity.
particular,
utilized
Monte
Carlo
methods
to
determine
layout
scheme
for
wells
under
these
conditions.
However,
there
is
often
a
substantial
computational
load
incurred
due
multiple
calls
model.
Hence,
employed
back-propagation
neural
(BPNN)
develop
surrogate
model,
which
could
substantially
reduce
load.
We
considered
dynamic
plume
migration
process
GPMN.
Consequently,
formulated
long-term
GPMN
optimization
conditions
with
aim
maximizing
accuracy
each
period.
The
spatial
moment
method
was
used
measure
approximation
degree
between
interpolated
actual
plume,
effectively
evaluate
superior
accuracy.
Traditional
easily
trapped
local
optima
solving
so
grey
wolf
optimizer
(GWO)
algorithm
solve
A
hypothetical
example
designed
evaluating
effectiveness
our
method.
results
indicated
that
BPNN
fit
input–output
relationship
from
as
well
significantly
GWO
solved
improved
solution
distribution
period
be
accurately
characterized
by
optimized
network.
Thus,
combining
addressed
problem
uncertainty.
developed
stable
reliable
methodology
optimally
designing